GEOMETRY

BY

MI S

S O

.

GEOMETRY (JEE-OM-I-TREE) – N.

The branch of mathematics concerned with the properties of and relationships between points, lines, planes, and figures.

GEOMETRY IS ANCIENT.

The earliest records of geometry can be traced to ancient Egypt and the Indus Valley from around 3000 BC.

EUCLID

Euclid, a Greek mathematician, wrote The Elements of Geometry.

He presented geometry in a practical form known as Euclidean geometry Euclid’s was not the first important early texts on geometry.

POINT

An exact location in space; named by a capital letter

LINE

A straight path that extends forever in opposite directions; named by two points on the line

RS

R

S

LINE SEGMENT

A part of a line with two endpoints; named by the two endpoints

PZ

ZP Q

PLANE

A flat surface that extends without end in all directions

RAY

A part of a line with one endpoint that extends forever in one direction; named by the endpoint first followed by another point on the ray

ANGLE

Two rays joined at a common endpoint called the vertex; named by the vertex or the vertex and a point on each ray

VERTEX

The point on an angle or polygon where two lines or rays meet; named with a capital letter

Vertex

RIGHT ANGLE

90 degrees

Square corner

Little box

ACUTE ANGLE

Less than 90 degrees

OBTUSE ANGLE

More than 90 degrees

STRAIGHT ANGLE

180 degrees

Straight line

http://www.youtube.com/watch?v=yptZt9hwrzU&safety_mode=true&persist_safety_mode=1&safe=active

ACTIVITY 1

Build all 4 angles with your bodies on the carpet. Each group will have 4 students in it.

Miss O. will come around to take a photo of each angle for the website!

ACTIVITY 2

Play “Simon Says” with each hand motion that represents a geometric term we learned today!

INTERSECTING LINES

Lines that pass through the same point

PARALLEL LINES

Lines that never intersect

PERPENDICULAR LINES

Lines that form right angles (90 degree angles)

All perpendicular lines are also intersecting lines!

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

WHAT GEOMETRIC TERM IS REPRESENTED?

TALK AND TURN:

In the world around you, where do you see geometric figures in real life every day?

Make a list with your partner of at least 3 ways!

FIND ALL THE ANGLES